G f mcmahon



April 20, 1937. G, F. MGMAHON 277429 CIRUT INTERRUPTEH AND ARG Ll'iTlNGUSHlNU LIQUID THEHE'OR Original Ellfd March 1933 2911 @inval Rene-wad l.

Appl

5mm of lille El. if type :me the nllu'nllfnm mpniles: lfm/stained ln lli@ Hummm nlfrnmjl employed ln nulli l Y ein this above mentioned uses, im 'mn thm' if um' zum. ve l.m1111alns A l nw? the tendency nf ,nnza um? am and mail may, und?? hn lnflunn@ nf al. L

sb tbn Gama thm nn fm ellzllrri=lyiln actlun which lend@ ll "fr nf 'electrical ennrgy ln additlen in llnlie so lnng as; the device carries leml'en' any release nf nndary encrg, :lf www 6. pfm MMU 0f the fuse 2L bly-ahw *Jl-1n um l, me Ilm; lelfrimlill :ated 'lo im, 1deheencn Rnd r* l mediums having in@ two valuable praga" lm'med. Thr@ ls herald-.f :l es above referred to are known. Se@ Schwnt- 'l Atrlcsll energy at highA f; 5: Cnnmd patent, Reissue No. 14:879? ane ing of the link is n d-@Slrnnle man in ld Patent No. 1,862,317, and ma? F951 first. ln 'the preferred lnrm fm l Nn, .966,901, issued July 17. 1934. The said menhanlcnllgf the terminal an lll-lul; msclnsures relate to the provision of a sullble retracted by the sp1-i' mnd, 1l liquid nr solid dielectric for the same class nf sa metal vapor for a sclld cnn-juntar. wvlle as the dielectric mediums herein disclosed, @my under auch 'eleafse of lwzll nl. l'llgll mmm d- :and lkw llnulds and solids herein clisclord muy turn is im" lhs dlnlncmln tn be Lawinen d ved ln structures auch an are danlnsed am! mw zmnglnm This lllanwsnld pulente; und iwi bei. fxnlwlmll: Ew uw il" wrnlll! I inn dnvnlnpmnl nl inse-x in a maw s: llama nids anfslfol: solids nl illu, tmf @1n-gens fl il conductivity of the ionized gases and vn :'inonld noi` release combustible liquids. vizio,

n gn because upon venting in the tttm olifV this would result in increasing 'the enemy l.;

d. .n nddition to iricrcnsinel the ci i iiiciures and the perifonnci.

' "c end. clioi' action which.. it c that oi' deonizing the ing material here hcw. n complex consists esscntially in reducing illu),

Probably this action is physical as well aS f"" l. und el.. rinal. 'The` desired result is i'lon ol current iow and the interposition tveen the tcfrninaic di e. dielectric o n strength that c nrc is unable t0 restriim or reestablish itseli. ii the fuse vente to dimos phare, it is desirable that the ejected material chould not ne inflammable, noxious, or corrosive. Fiectricai devices of the class to which this invention relates, such. as fuses, circuit transformers, etc. are often required to stond in exposed situations and under load foi' long per-iode of time. Particularly fuses of the type 'nf-cem referred to, which have glass container. permit tht entry of light to the dielectric liquid. They are thus subjected to adverse influences over long periods. During euch periods, heat due current flow or to atmoepherlc conditions and nic eiiects, chiefly from sunlight. are appl'cli to the liquid. Hence, any tendency im' d dielectric to undergo a chemical change Lil the l.. i.

h nple opportunity to act.

lh iii-si object ot infJ precept invention is:

pmt-ide e, circuit interruptor of the self-contained or enclofscd type employing an arc oxtinlgpihAA lngf medium which is acted upon by the zw to tate circuit interruption.

ticuierly the nictiiod of preperlng and ntillzi'fi.Y il :i diminishing dielectric.

fthe-f' ollject is to improv.n the stahl end or the entirc device in felini nhject i5 to improve the nploying liquid 'licicctrics exenfi the unfiiul ille nl the s l. s to provider rin imp :d filled inse having dependable ieinty oi operation over extended periods time.

A further object is to provide an improve-rl fuse of the type above recitedA Other objects will appear from the following specification, drawing, and claims.

in the accomplishment of the above and other objects I employ as the preferred embodiment of my invention a. liquid filled fuse ofthe S. 8i C. type in which the arc extinguishing liquid is a halogen derivatve of a hydrocarbon iound to he suimlolc for its primary service of are delonization and having the necessary physical characteristics of boiling point. freezing point, density. etc.

liquid or series o liquids suitable from the above standpoint is disclosed in my aforesaid Potent No. 1,966,901. The liquid or class of liquids therein disclosed, even in the pure state, free of injurious reaction with water which, .may he contained in the inse casing, even though cupi d 'to sunlight. llowcvcr .ii air is pres-eng.,

. redete :vini ...cc cnc. fiori:

oi' rendo' ol" tine.

avide found desirable to chamber to receiv a pon. end Ease; evolved upon blow;

sufficient ig of the fuse casim: t.) ation of the fuse except on fr Y his expansion chambcr may' neutral gee, out preferable." if.V i Jvhen so air iilled the oxytiv cf nde to react with the orf lo. even though impuritiesJ ha.

ch. condensation so iariensilzsiel When il punti .o ai i; :t will generali-y accelera. the brecha? l i lo dielectric.

Now, according to one pliage of t ie vention, introduce into the diclc chilly auilinf. lt innv l tive of aniline, mich im oniiine: f

ludo in this einer, romgiizli'iiv .vl` coi'itainng derivatives of fnl-lions and also aliphatic ltyrliocoi materials may he employed The materiell. moet not interfere with the oriivincti im und dielectric propt-iile:n ci' ille iiili xshould not he used in lern Quanti.. Should it cause deterioration oy its cf with tl im pui-itivf` or the products oi" d the , "with il f liquidv i' employed .11. ti material may in tn@ c "rino particular use. A. the like may hc alim. o

, tetrucliloroethygiene, or

im w, in oi'dcr with 'UW morir.-

-. fenilwf, l rfi'iipii o. .a

e foco. pdv-1in i ill pulci.;

nd "mi The slcfvre 2 forni" tho iowcf MM i electric terminal for the d ce. it Lne end of the glass sleeve` i u metallic erulc 3 similarly cemented. The errule E has un e tension forming an enlarged chamber d, and this chamber may be provided interncllv with omino; fins 5, preferably formed il; the ehehe: of mi annular 5l 1 `t metal rings or n hellen". coli o' tlv.

trip nmol: llc purpose. o' .fiiortli Superficial cooling, anu' lizondcnomg enrico lo l, cally lef l? :chamber 43,01# may "wl smaller meu. The mp 3 d in place y a .sua-liable ill-flu' glvlz; a 'nml nl lmmvn. Strcng fmlplme 3f lelfmsirg be! mbemal pressure lA adapted lo be conflnecl ls provided in me 1111x7192' parl of he fuse hnusng. This tubular cil mines 35 or passageway is dallm'fd by a @lellva 9. wlllch im mail of insulation such as ber nl' succrmvs:

m a` sullmhln imnrsgnasc s l, :fm-1v1 f par or the llkau Th2 slffve 9 ls suppfllrtw at n nimm wil m s mnsvffl'sl, head or b-Lrrlr pla :lfm U which cxlernally threaded and efonleratea wlll threads [armed internally anhin thv ferr-ul@ "lha: `lnrlmds lfldlmlml fill; l preferably have :l

@terminal strength mames?` mmm? my pn ss sl'felf@ l. so that l1' e'. .m'c is generatwi wil/hln the glass llM-:l m' barrier pillar: lli mm" be r1 l opening or may have rau l Je Some uf 'he p..

uber 2.

la@ warmly lit. The intention 1s to ima-e mme when Uhr pressure* wil u the glass sleeve ses lo predetermined value. Tm: theory of tlm etonstruclion is to ret/ain as much prssuf@ with lys lha sleeve l as it 1s safe to carry, and progressively releasing the same lf it tends to rise mauve prvfletmmlned limits. by rst expelling the sleeve nl und lhen the head H).

The tubular chamber or passageway may be clnlfgnmd as an arclng chambr im the present y @ovina im the reason that. ha iusllll lnlz dlsposed tlwxpln nr mmvdlally adjacent thv uppr und tlwiemf, and upon fusing of the fusi bh: link i3, Lhe pressure so generated and the heal incidental lo fusion and the onsequent are dow ml, strike ihr: glass Slew() l, but, ls cnnlmd wthm the insulating slefave lr link, i3 ls: prefrbly a ll'vlr:

nlwlmnlnf l sil ,Uw ml Til i mmml'ied in the lem'lnals fh line lnmm lll@ wir@ 2? su l Q-W'mlrlfll and the termiml! enffl iT, hm; Y in lollig; Lu lne :1l: msfacnry is) have thu lmuid fill powcl below the hardy oi' the 'uslbll lnll 5l ril heating of said link is not influflmwl *m mw grml extent by the presence Ui' the View va n :r part of lhv l^- Henneman ulti-MEN. argon, or m n nofllslel fulmini the filling lim, l m0 Solulwlf ihm zzL The liquid duw? Till lar passageway or chamber 8, the liquid so projected is discharged into the chamber 8 and is acted upon by the arc which tends to vaporize it. The liquid and vapor iiows at great rapidity, in fact with violence through the said chamber or Apassageway 8, within which a corresponding length of the arc is conilned. This violent flow of the arc extinguishing liquid and the iluids resulting therefrom, which are gas and vapor. in passing through the chamber U tend to deionize by condensing upon the charged particles and combining chemically with the metallic vapors and to blow the metallic vapors which were formed by melting of the fuse and strain wires, endwise into the chamber 4.

The connecting plate I6 is preferably provided with a series of openings, which allows gases and vapors to now therethrough towards the chamber 4, but if the pressures are suillcient, this connecting plate i8, and the upper terminal Il carried thereby, may be driven into the chamber 4.

The continued downward movement of the terminal I5 tends to submerge it in the liquid contained within the housing, and such movement extends the length of the arc, and also brings more oi' the arc extinguishing liquid within the influence of the arc with further flow o1 the gaseous medium. that is, vapors and gases, out through the passageway 8, tending to deionize the arc both by condensation upon the charged particles and by the constant substitution of a non-ionized dielectric medium, and an outward sweep of the ionized gases and vapors.

Ii the blow is so violent as to require expulsion of the sleeve 9, it may be driven upwardly into the chamber I; likewise, the head or barrier plate i may be expelled. In the event that the condensing and cooling capacity of the chamber l and its cooling means, is not suiiicient to keep down the pressure below that for which the cap 6 is adjusted, this cap may be blown oif to vent the chamber l and connected parts to atmosphere.

For usual conditions of protection. the blowing is not so violent as to require release of the vent cap E.

The arc extinguishing dielectric, which is ernployed in the present fuse, is preferably composed chierly oi a halogen substitution product of a hydrocarbon.

As explained in my copending application, Serial No. 503,481, trichloroethylene iCzHCial and tetrachloroethylene (C2014) in suitable proportions may be employed to advantage in devices of this character. Furthermore, solid dielectrics of the same general class, such, lor example, as hexachloroethane iCzCi) may be dissolved in one or the other of the aforesaid liquids, or in a mixture of both. The mixture of trichloroethylene and tetrachloroethylene is generally free from decomposition by sunlight in the presence of moisture, but both tetrachloroethylene and trichloroethylene are easily oxidized 'under the action of light when they are allowed to be in Contact with atmospheric air at ordinary atmospheric temperatures. Tetrachloroethylene is decomposed in sunlight in the presence of oxygen into phosgene lCOClz) and trichloroacetyl chloride (CChCOCl or CzChO) Trichloroacetyl chloride is easily oxidized further by water to form trichloroacetic acid iCzHClOs and free hydrochloric acid. This hydrochloric acid oi course tends to attack the metal parts oi the fuse or the metallic structure with which it is in contact. In the present construction, the ierrules I and 2 oi.' the fuse are amano made of brass. which is readily attacked by chlorine. The terminals il and I are also made of brass, and the spring and shunting cable 21 and 26, respectively, and their connect-ed parts, are all made of brass or copper. While the fuse element is preferably made of silver, and is less subject to attack, nevertheless the formation oi hydrochloric acid within the interior of the iuse housing, which is highly undesirable, tends to cause deterioration of the fuse element and to result in possible change of rating, and also to contaminate the arc extinguishing liquid itself.

Trichloroethylene is also easily oxidized in the sunlight in the presence of oxygen. While in the preferred embodiment of the invention, the fuse housing is hermetically sealed, the upper part oi the housing is preferably lled with atmospheric air. Also a certain amount of oxygen tends to enter in the course oi' manufacture through absorption by the surfaces of the various materials entering into the construction of the device.

The decomposition of trichloroethylene results chiefly in carbon dioxide, hydrochloric acid and phosgene. While there may be various inter mediate products in the decomposition of trichloroethylene and tetrachloroethylene, the final products are acid in character, corrosive to the metal parts of the fuse.

As previously explained in my copending appli cation, the mixture of these two liquids in approximately the ratio of ninetyfour parts of tetrachloroethylene and six parts of trichioroethylene gives a dielectric arc extinguishing me dium which has the advantage of a low freezing point, high dielectric strength, relatively high boiling point, and excellent arc extinguishing properties. Hexachloroethane (CaCla) may be added up to about 25% of the mixture of trichloroethylene and tetrachloroethylene. The percent oi halogen content ichlorine) in the resulting liquid will be of the order of 80% to 85%, although it may be of the order of 75% to 95%. depending upon the halogen compound used.

To the arc extinguishing liquid consisting of one or more oi the above halogen derivatives of a hydrocarbon I add a small amount, for example, less than x15 of 1% by weight of aniline as a preservative.

Aniline is basic in character. It reacts with acid substances readily, forming stable neutral compounds which do not readily corrode metals so long as aniline is present in the liquid. It tends to combine with any oi the impurities which are contained within the arc extinguishing liquid. or liquids such as tetrachloroethylene, trich1oroethylene, and the like, and it may serve as a preservative of these liquids for general purposes, such as fire extinguisher service, for use in electrical apparatus such as transformers, liquid lled bushings, cables, and the like.

I believe it is broadly new to employ aniline or any of its derivatives as a preservative oi' tetrachloroethylene or trichloroethylene, or any of the halogen derivatives of hydrocarbons such as are employed for tire extinguisher service, or the other uses to which I have referred. Also, aniline, or its derivatives, serve as an excellent purifier in the manufacture of chlorine derivatives o! hydrocarbons or other halogen derivatives of hydrocarbons. Instead of using aniline, any one oi its derivatives which react readily wtih oxygen or chlorine, or the other halogens or acid impurities which it is desired to remove, may be employed instead. Many of the derivatives of aniline, in-

cluding commercial coal tar dyes, may be employed instead of the aniline itself.

In the process oi purification oi.' triohloroethylene or tetrachloroethylene or the like, I add a suitable amount of aniline or its derivatives. The amount employed is preferably in excess oi that necessary to combine with the impurities of the liquid to be treated. The liquids are thoroughly stirred and allowed to stand for a time to allow in contact between the aniline and the impurities to the necessary extent. Aniline reacting with hydrochloric acid, which is a common impurity in chlorinated hydrocarbons, forms aniline hydrochloride. Reactlng with trichloracetic acid it forms trichloroacetanilide. Reacting with phosgene it forms chlorobenzamide. Aniline, and many of its derivatives, readily reacts with oxygen.

Most of the compounds formed by the reaction of aniline, or its derivatives, with oxygen and halides, tend to float upon the top oi' the arc extinguishing liquid, but are heavier than water.

The same is true o1 the forms of such compounds in. purifying tetrachloroethylene or trichloroethylene. The aniline and its products of reaction with oxygen and the halogens are substantially insoluble in halogen derivatives.

Certain other acid substances may be present in tetrachloroethylene and trichloroethylene, and the anlline which I employ as a preservative reacts with such acid substances to remove the same from the liquid. In the refining or purifying of halogen derivatives of the hydrocarbons with aniline, the precipitate is first formed and the liquid may then be iiltered and distilled to remove the impurities. Distiilation, however, is

optional.

Instead of employing aniline as a preservative, that is, a neutraliser and acid remover i'or the dielectric bath, I may employ other materials Ml which do not interfere with the dielectric properties and arc extinguishing characteristics of the same, when used in proper proportions, but which serve to react with the impurities that otherwise would cause breakdown of the liquid and attack of the metal paris.

As above mentioned, aniline dyes and products derived from aniline may be utilized. In addition, various nitrogen containing compounds oi.' aromatic hydrocarbons. such, for example, as hydrazobenzene iC5H5NH-NH-CH5J azobenzene CsH5N:NCHs and azoxybenzene fClzHmNzO) as substitutes for aniiine, may be used. The above compounds are all coal tar derivatives. Also some of the amino compounds of the aliphatlc series, such as isopropylamine, acetamld.

etc., may be employed as preservatives.

Whereas, in the above disclosure, I have referred to the dielectric bath, where the same has been discussed in detail, as consisting oi' one or more halogen derivatives of aliphatic hydrocarbons, I find that halogen derivatives of aromatic hydrocarbons may be employed for this service. that is, as an arc extinguishing liquid in circuit interrupters broadly and in liquid iilled fuses specically, and as a dielectric medium for electrical apparatus, such as high tension terminals, high tension cables, transformers and the like.

The preservatives which I have above disclosed as suitable for use in connection with the aliphatic halogen derivatives may he employed in preserving the aromatic halogen derivatives and/or purifying the same.

I therefore wish to include within the present invention the use of aliphatic and aromatic nitrogen containing compounds as preservatives and purifiers of halogen derivatives of hydrocarbons of either the aromatic or aliphatic group. The aromatic compounds are generally called the ring compounds, being chieiiy exemplified in benzene (Cslal and its derivatives. A number of compounds comprising halogen derivatives oi aliphatic hydrocarbons, chieiiy compounds oi fluorine and chlorine, or both oi them, have been The substances which are solids and liquids may be employed in fuses and for dielectric baths as herein described. I have also found that certain bromine derivatives of aliphatic hydrocarbons may be employed, some of the same being the following:

D Dogrties agrees cencon Composition tigrado boilgrade Natura g ing point freezing point 1.959 172 2i Liquid 3. 42 189. 5 4B. 4 Solid.

B96. l l. H 147. 5 7. 7 Liquid 2, 4H 97. 8 52. 8 Liquid 2. 964 151 .l Liquid Decoinposed Liquid 2,304 172 4 4 Liquid 203 4 Solid. d c 226 57 Solid1 2. 708 ll Y Liquid.

Bromine derivatives are more easily oxidized by water and oxygen of the air than chlorine derivatives. Iodine derivatives may also be employed. In all of the above, the aliphatic and aromatic nitrogen containing compounds which I have above described, and a typical and preferred form of which is aniline, may be employed as purifiers and preservatives.

I am aware that paraiin hydrocarbon has been proposed as a preservative of tetrachloroethylene, but I wish to point to the fact that paraffin hydrocarbon is neutral with respect to acid impurities. and. cannot combine with and remove the impurities.

Also. as a dielectric medium for extinguishing arcs, paraiiin hydrocarbon is not desirable in that it is combustible, and adds to the energy liberated upon venting of the fuse to atmosphere. In other words, it tends to increase instead of decrease the flash and flame, as a large amount is required to preserve the liquid and prevent injury by the acid content.

The use of aniline or like nitrogen containing compounds, derivatives of hydrocarbons in conjunction with any of the above liquids or solids. has a further virtue that such preservative may combine with oxygen and stili be available as a neutralizing medium for free acids or acid form- 'lli ing compounds or radicals that may be iound in or result from breakdown of the dielectric medium.

Aniline may also be called a reducing agent as it is easily oxidized, taking oxygen away from some other source. There are many reducing agents, I have found, which act much the same as anillne in this respect, which do not contain nitrogen in the molecule, such as pinene (CiuHis), cymene (CwHliLlimonene (CwHm) and (CsHsOz) hydroquinone, etc. 'Ihey are not as eiicient, however, as aniline, but I wish to claim the right to use these if and when the occasion should permit.

'I'he aniline or equivalent puriier or preserva.- tive has, for my purposes, the valuable features with respect to the liquid, first, that such purifier will combine with free oxygen to prevent it attacking the dielectric; second, the purifier will react with any acid contained in the dielectric or released by breakdown of the same; third, that such preservative does not substantially interfere with the properties and functions of the dielectirc and, fourth, that the combination products of such preservative with injurious impurities do not substantially injure the properties and functions of the dielectric.

The solid substitution products oi a hydrocarbon containing a halogen may be employed in a fuse of the type disclosed in the patent to Ringwald, No. 1,862,317, to which reference has previously been made.

The halogen derivatives of aromatic hydrocarbons may be employed with or without the preservative herein disclosed for arc extinguishing and general dielectric purposes, within the scope of my invention.

I do not intend to be limited to the precise details herein shown and described, nor to the specic compounds which I have referred to herein as classes suitable for the service herein referred to.

I claim:

l. In a device of the class described, the combination of a closed housing, a pair of metallic terminals between which an arc is adapted to be formed, and an arc extinguishing liquid in the housing, said liquid comprising a halogen derivative of a hydrocarbon and containing a small amount of an aromatic nitrogen containing compound.

2. In an electrical device, a closed housing comprising two chambers. an electric fuse in said housing, one of said chambers being adapted to contain an arc extinguishing liquid, the other of said chambers being adapted to contain air, an arc extinguishing liquid in said first chamber, said liquid being subject to reaction with the oxygen in the air chamber to yield an acid, and a neutralizing agent in said liquid capable oi' preventing injury to said liquid by the oxygen and capable of reacting with the acid content of the are extinguishing liquid.

3. In a device of the class described, the combination of a housing comprising an insulating sleeve having metallic ferrules forming terminals externally, a pair of metallic fuse terminals in said housing. a fuse electrically connecting said fuse terminals and adapted to be fused by excess current flow through the device, metallic connections between said fuse terminals and said external terminals, an arc extinguishing material in said housing adapted to be acted upon by the heat oi the arc to form a gaseous arc extinguishing medium, said material comprising a comand a protective compound in said housing, said protective compound inhibiting migration of said strongly active substance from said material to said metallic parts of the device.

4. In a device oi the class described, the combination of a housing, a pair of fuse terminals, a fuse between said terminals, said fuse being adapted to be melted upon the flow of excess current through the device, an are extinguishing material in said housing, said liquid comprising a halogen derivative oi a hydrocarbon and containing a small amount of a compound having an alkaline reaction and easily combinable with oxygen.

5. In a device of the class described, the combination of a. housing, a pair of fuse terminals, a fuse between said terminals, said fuse being adapted to be melted upon the flow of excess current through the device, an arc extinguishing material in said housing, said material comprising a halogen derivative of a hydrocarbon and containing a small amount of coal tar dye.

6. In a device of the class described. the combination oi a housing, a pair of metallic terminals between which an arc is adapted to be formed. an arc extinguishing material disposed to be acted upon by the arc to evolve a gaseous are extinguishing material. said arc extinguishing material being adversely affected by contact with the atmosphere and causing corrosion of the metallic parts, and a protective substance which does not substantially interfere with the arc ex` tinguishing properties of said material for inhibiting the said corrosion.

7. In a device of the class described, the combination of a housing, a pair of metallic terminals between which an arc is adapted to be formed. an arc extinguishing material disposed to be acted upon by the arc to evolve a gaseous arc extinguishing material, said arc extitnguishlng material being adversely affected by contact with the atmosphere and causing corrosion of the metallic parts, and a protective substance cooperating with said material to protect the same from atmospheric influences, said substance being relatively small ln proportion to the material and causing no substantial interference with the arc extinguishing properties oi' said material.

8. In a device of the class described, the combination of a closed housing, a pair of metallic terminals between which an arc is adapted to be formed in the housing, and a charge oi arc extinguishing liquid in the housing comprising tetrachloroethylene containing a relatively small amount of aniline dissolved therein.

9. In a device of the class described, the combination of a closed housing, a pair of metallic terminals between which an arc is adapted to be formed in the housing, and a charge oi' arc extinguishing liquid in the housing comprising tetrachloroethylene containing a relatively small amount oi' a reagent capable of combining with and neutralizing any free acid in the housing.

l0. In a device of the class described, the combination oi a closed housing, a pair oir metallic terminals between which an arc is adapted to be formed in the housing, and a charge of arc extinguishing liquid in the housing comprising tetrachloroethylene containing a relatively small amount oi a basic compound capable of reacting with contained acid impurities.

11. In a device of the class described, the combination oi a closed housing, a pair o! metallic terminals between which an arc is adapted to be formed in the housing, and a charge ci arc expound of a strongly active chemical substance.

tinguishing liquid in the housing comprising tetrachloroethylene containing a small amount of a nitrogen containing derivative of a hydrocarbon.

12. In a device of the class described, the cornl blnation of a closed housing, a pair of metallic terminals between which an arc is adapted to be formed in the housing, and a charge of are extinguishing liquid in the housing comprising a halogen derivative of a hydrocarbon containing a small amount of a nitrogen-containing derivative of a hydrocarbon.

1B. In a device of the class described, the combination of a closed housing. a pair oi metallic terminals between which an arc is adapted to be formed in the housing, and a charge of arc extintingdishing liquid in the housing comprising a halogen derivative of hydrocarbon of the aromatic class containing a small amount of a nitrogen-containing derivative of a hydrocarbon.

14. In a device of the class described, the combination of a closed housing, a pair of metallic terminals between which an arc is adapted to be formed in the housing, and a charge of arc extinguishing liquid in the housing comprising a halogen derivative of a hydrocarbon containing a relatively small amount of a compound capable oi combining with the oxygen of the air, said amount being not substantially more than onetenth of one per cent by weight.

l5. In a device of the class described, the combination of a closed housing, a pair of metallic terminals between which an arc is adapted to be formed in the housing, and a charge of arc extinguishing liquid in the housing comprising a halogen derivative of an aliphatic hydrocarbon containing a relatively small amount of a nitrogencontaining derivative oi a hydrocarbon.

16. In a device of the class described, the combination of a closed housing, a pair of metallic terminals between which an arc is adapted to be formed in the housing, and a charge of arc extinguishing liquid in the housing comprising tetrachloroethylene, trichloroethylene and aniline.

17. In a device of the class described, the combination of a closed housing. a pair of metallic terminals between which an arc is adapted to be formed in the housing, and a charge of arc extinguishing liquid in the housing comprising trichloroethylene in mixture with tetrachloroethylene in the proportions oi' substantially 10% to 6% of the former and 90%` to 94% of the latter containing a relatively small amount of a dissolved preservative which is oxidzabie by contact with air.

18. In a device of the class described. the combination of a closed housing, a pair of metallic terminals between which an arc is adapted to be formed in the housing, and a charge of arc extinguishing liquid in the housing comprising hexachloroethane and tetrachloroethylene, said liquid containing a relatively small amount oi' a preservative which is oxidizable by contact with t atmospheric oxygen at room temperatures.

75 upon exposure thereto, without substantial injury to the properties oi said composition o! matter for arc extinguishing purposes, said amount being not substantially more than one-tenth of one per cent by weight.

20. In a device of the class described, the combination of a housing, a pair of metallic termiA nais between which an arc is adapted to be formed in the housing, a charge of arc extinguishing material in the housing in position to be acted upon by the heat of the arc to evolve a gaseous arc extinguishing medium, said material comprising a halogen derivative of a hydrocarbon with a small amount of basic material. the compounds formed by said basic material and the impurities contained in said first material being substantially insoluble.

21. In a device of the class described, the combination of a housing, a pair of metallic terminals between which an arc is adapted to be formed, a charge of arc extinguishing material in the housing in position to be acted upon by the heat of the are to evolve a gaseous arc extinguishing medium, said material comprising a halogen derivative of a hydrocarbon and a small amount of a reducing agent.

22. in a circuit interrupting device having a housing pervious to iight, metallic conducting parts, a charge of liquid arc extinguishing material in the housing in contact with said metallic parts. said liquid under the action of light or heat and in contact with air or moisture causing corrosion of said metallic parts, and an inhibitor present in small amounts as herein described for preventing corrosion of said metallic parts when said liquid is subjected to the aforesaid influences.

23. In a circuit mterruptlng device of the class described, comprising e. closed chamber containing metallic conducting parts, a charge of liquid comprising a halogen derivative oi' a hydrocarbon and a body of inert gas contained in said chamber above said liquid.

24. A liquid charged fuse having a charge of liquid comprising a halogen derivative of a hydrocarbon and a body of nitrogen gas contained in the fuse above the liquid.

25. A fuse having a closed housing. metallic parts including a fusible link in the housing, an arc extinguishing material in the house in cloro proximity to said metallic parts. and a charge of an inert gas in the housing into which gas metallic vapor produced by blowing of the link is pro- Jected.

26. In a circuit interrupter having a housing pervious to iight, an arc extinguishing liquid comprising a halogen derivative of a hydrocarbon and a coal tar dye permeating the same, said dye being capable of absorbing a portion of the spectrum of the sunlight falling upon the liquid to avoid deterioration of the liquid.

27. In a liquid containing fuse having a housing pervious to light, an arc extinguishing liquid comprising a halogen derivative of a hydrocarbon and a coal tar dye permeating the same said dye being capable of absorbing a portion oiV the spectrum of sunlight falling upon the liquid and being further capable of combining with free oxygen in contact with the liquid and capable oi' neutralizing decomposition products of the liquid to render said products non -corrosive upon metallic parts of the fuse.

28. In a. device oi the class described. a housing containing metallic conducting parts, a charge of normally neutral liquid dielectric ln fill contact with the metallic parts in the housing, said liquid being subject to influences which cause it to develop corrosive properties, and a. nitrogen containing compound present in small amounts for preventing the development of said. corrosive properties.

29. An arc extinguishing liquid for circuit interrupters, said liquid comprising tetrachloroethylene. trichloroethylene and anilne.

30. As an arc extinguishing liquid for use in circuit interrupters, trichloroethylene in mixture with tetrachloroethylene in the proportions of substantially 10% to 6% of the former and 90% to 94% of the latter containing a relatively small amount of a dissolved preservative which is oxidizable by contact with air.

31. An arc extinguishing liquid for use in circuit interrupters, a liquid comprising hexachloroethane and tetrachloroethylene, said liquid containing a relatively small amount of a preservative which is oxidizable by contact with atmospheric oxygen at room temperatures.

32. As an arc extinguishing liquid for use in an electric fuse, a. halogen derivative of hydrocarbon and a small amount of a preservative capable of combining with acid impurities to neutralize the same, and capable of combiningwith free oxygen upon exposure thereto, without substantial impairment of the properties of said liquid for arc extinguishing purposes, said amount being not substantially more than one-tenth of one per cent by weight.

33. In an electrical device, a closed housing comprising two chambers, circuit interrupting means in said housing, one of said chambers containing an arc extinguishing material, the other of said chambers containing a gas. and a neutralizing agent in the arc extinguishing material capable of preventing the formation of injurious compounds by contact of the gas therewith.

34. In a circuit interruptor, a closed housing, metallic parts including separable terminals between which an arc is adapted to be drawn. an arc extinguishing material in the housing in effective proximity to said terminals, and a charge oi an inert gas in the housing, the products of the arc being discharged into said gas.

35. In a circuit interrupter, a closed housing including a cooling chamber having an extensive suriace and Containing a charge of an inert gas. separable terminals between which an arc is adapted to be established in the housing disposed adjacent said chamber, and an arc extinguishing material in the housing in close proximity to said separable terminals and adapted to be acted upon by the arc between them, the products of the arc being discharged into said cooling chamber.

35. In a circuit interrupting device having a housing pervious to iight, in combination, metallic conducting parts, a charge of liquid arc extinguishing material having a halogen content of over by weight in said housing in contact with said metallic parts, said liquid under action of light or heat and in Contact with air or moist- A ure causing corrosion of said metallic parts, and

an inhibitor present in small amounts as herein described for preventing corrosion oi' said metallic parts when said liquid is subjected to the aforesaid influences.

37. In a circuit interrupting device, in combination, metallic conducting parts, a charge o liquid arc extinguishing material having a halogen content of over 75% by weight in contact with said metallic parts, said liquid being disposed to cause corrosion oi' said parts on change in temperature thereof in contact with air or moisture, and an inhibitor present in small amounts as herein described for preventing corrosion of said metallic parts when said liquid is subjected to said influences.

38. In a circuit interrupting device having metallic conducting members, in combination, a charge of liquid arc extinguishing material having a halogen content of over 75% by weight in contact with said conducting members. said liquid in the presence oi air or moisture being disposed to cause corrosion of said conducting members, and an inhibitor present in small amounts as herein described for preventing corroslon of said conducting members on the occurrence of said conditions.

39. In a current conducting device adapted to remain in service undisturbed for extended periods of time, the combination of a casing sealed to exclude entrance of air and moisture, a metallic electrical conductor in said casing, said electrical conductor having circuit completing connections outside the casing, a halogenated hydrocarbon forming a dielectric i'llling for said casing for insulating said conductor and for extinguishing any electric arc that may be formed Within said casing, and a corrosion inhibitor in said casing dispersed in said dielectric filling sufficient to combine with chemical impurities which may be formed from confined air and moisture but insuilcient to produce any substantial impairment of the dielectric or arc extinguishing properties of the dielectric filling.

40. The combination of claim 39 wherein the corrosion inhibitor comprises aniline.

4l. The combination oi claim 39 wherein the inhibitor is a nitrogen containing derivative of a hydrocarbon.

42. The combination of claim 39 wherein the dielectric filling is a liquid comprising tetrachloroethylene and the inhibitor is an oxidizable hydrocarbon substitution product capable of combining with chlorine compounds.

43. The combination of claim 39 wherein the dielectric iling comprises trichloroethylene substantially 10% to 6% and tetrachloroethylene substantially to 94% and the inhibitor is an amino compound of hydrocarbon.

44. The combination of claim 39 wherein the inhibitor is an oxidizabie organic compound.

45. The combination of claim 39 wherein the dielectric lling is a liquid comprising trichloroethylene and the inhibitor is an oxidizable hydrocarbon substitution product capable of combining with chlorine compounds.

GEORGE F. McMAHON.

CERTIFICATE 0F CORRECTION.

peinent No. 2,077,429. April 2o. 1957.

GEORGE F. MCMAHON.

It is hereby certified that error appears in the printed specification of the above numbered patent requiring Correction as follows: Page 6,. first column, line 75, claim 3, after' the syllable "Com" add the syllable, words and Comma pound of a strongly active Chemical substance.; second column, line 40, Claim '7, for "extitnguishing" read extinguishing; and page 7, first column, line l, claim 1l, strike out the Words and comma "pound of a strongly active chemical substance,"; and that the said Letters Patent should be read with these corrections therein that the same may Conform to the record of the case in the Patent Office.

Signed and sealed this 15th day of July, A. D. 1937.

Henry Van Arsdale (Seal) Acting Commissioner OI" Patents. 

